• Structural Engineering and Mechanics
• /
• 제48권5호
• /
• pp.661-679
• /
• 2013

In this work, the safety performance of a commercial motorcycle helmet already placed on the market is assessed. The assessed motorcycle helmet is currently homologated by several relevant motorcycle standards. Impacts including translational and rotational motions are accurately simulated through a finite element numerical framework. The developed model was validated against experimental results: firstly, a validation concerning the constitutive model for the expanded polystyrene, the material responsible for energy absorption during impact; secondly, a validation regarding the acceleration measured at the headform's centre of gravity during the linear impacts defined in the ECE R22.05 standard. Both were successfully validated. After model validation, an oblique impact was simulated and the results were compared against head injury thresholds in order to predict the resultant head injuries. From this comparison, it was concluded that brain injuries such as concussion and diffuse axonal injury may occur even with a helmet certified by the majority of the motorcycle helmet standards. Unfortunately, these standards currently do not contemplate rotational components of acceleration. Conclusion points out to a strong recommendation on the necessity of including rotational motion in forthcoming motorcycle helmet standards and improving the current test procedures and head injury criteria used by the standards, to improve the safety between the motorcyclists.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2008년도 정기 학술대회
• /
• pp.573-578
• /
• 2008

Finite element analysis of impact response of a motorcycle helmet is presented in this paper. The finite element LS-DYNA3D code is used to simulate the impact response of the helmet including of plastic shell, foam liner, and magnesium headform. Since the maximum accelerations at center of gravity of the headform obtained by numerical analysis and experiment agree well, the numerical simulation is proved to be valid.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2007년도 정기 학술대회 논문집
• /
• pp.451-456
• /
• 2007

A finite element analysis and experiment study of a motorcycle helmet are presented in this paper. The finite element LS-DYNA3D code is used to analyze the helmet. The test specimen, instruments, and setup procedures are described. Since the displacements and Von-Mises stresses obtained by numerical analysis and experiment agree well, the numerical simulation is proved to be valid.

• 한국산학기술학회논문지
• /
• 제16권12호
• /
• pp.8386-8393
• /
• 2015

이 연구는 오토바이용 헬멧에 통기성을 강화하고 내부의 냉각기능을 보완한 쿨헬멧(cool helmet)의 필요성과 쿨헬멧 구매에 영향을 미치는 요인에 관한 조사연구이다. 연구방법은 설문조사를 통한 방법으로서, 2014.5.20 ~ 28까지 구글닥스를 이용하여 오토바이 동호회를 대상으로 오토바이 운전자 197명을 조사하였다. 조사결과 오토바이 헬멧 착용 시 불편함을 느끼는 이유로서는 '덥고 답답해서'와 '헤어스타일이 망가져서'가 주요 요인으로 나타났으며, 5점 척도로 조사한 쿨헬멧의 필요성은 평균 3.9점, 쿨헬멧에 대한 구매의향은 평균 3.6점으로 나타났다. 한편, 쿨헬멧이 출시될 경우 오토바이 운전자들의 구매의향에 영향을 미치는 요인은 쿨헬멧의 필요성 인식정도(오드비는 6.52)와 오토바이 헬멧에 쿨기능을 장착할 경우 헬멧에 대한 추가지불 의향 가격(오드비는 1.77)만이 통계적으로 유의한 것으로 나타났다. 한편, 구매의향 분석에 의하면 쿨헬멧의 목표시장은 추가지불 가격이 4만원 이하의 비교적 저가형 쿨헬멧이나 10만원 이상 고가의 쿨헬멧 출시전략이 유효할 것으로 예상된다. 이와 같이 기존의 연구에서 시도되지 않은 쿨 헬멧의 구매의향과 관련된 연구가 이루어진 점이 이 논문의 기여라 할 수 있다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2007년도 춘계학술대회 논문집
• /
• pp.409-412
• /
• 2007

A motorcycle helmet is the best means to protect the head of bike's driver and it is directly connected to a driver's life. Prior to producing of the helmet, it has to be passed the process of impact test to evaluate of its safety. This test evaluates peak acceleration and H.I.C (Head Injury Criteria). This paper analyzes impact test with finite element method to find the behavior of helmet during the test. Also, the effect of impact sites on the helmet was evaluated to improve the thickness distribution of the helmet.

• 소성∙가공
• /
• 제16권5호통권95호
• /
• pp.370-374
• /
• 2007

A motorcycle helmet is very essential to protect the head of driver and it is directly connected to driver's life. Prior to producing the helmet, it has to be passed the process of impact test to evaluate its safety. This test evaluates peak acceleration and head injury criteria (H.I.C.). This paper simulates the impact test with finite element method to find the behavior of helmet during the test. Also, the effect of impact sites on the helmet was evaluated to improve the thickness distribution of the helmet.

• 한국항공운항학회지
• /
• 제18권1호
• /
• pp.58-63
• /
• 2010

Introduction : Head trauma is the main cause of death in aircraft crash. In a Michigan study of structurally survivable, fatal accidents, 80% of the fatally injured had received head trauma. We tried to develop a new helmet for passengers, and perform its efficiency test. Methods : An aircraft helmet requires an excellent protection against head trauma, lightness, and small volumes. In addition, it must be wearable, fire resistant, and non toxic when it is burning. We developed two new helmets made from silicone foam which met all theses requirements. One was thin (2.5cm), and the other was thick (6.3cm). These looked like a motorcycle helmet and had only a soft silicone as liner material without an outer hard shell. Therefore we can carry them easily inside aircrafts. The standard test for helmet is Snell's drop test. It measures the impact acceleration of head shaped metal wearing helmet during we drop it at certain heights. Impact sites were total 5 sites (front, back, right, left and top) for each helmet. All these sites were impacted twice. Results : The thickness of impact sites varied from 2.5cm to 6.3cm. The impact acceleration of 2.5cm thickness site when it was dropped from 1.0 meter was 379g. But, that of 6.3cm thickness site when it was dropped from 1.5 meter was only 163g. Unfortunately, both helmets didn't meet the Snell Standard for motorcycle helmets. Discussion : If we add suitable outer hard shell, and change its thickness and design, the efficiency will be increased. A study indicated that helmet could reduce the risk of head trauma up to 85%. We made helmet for passengers in aircraft crash for the first time. If we improve its weak points, it will decrease the frequency of head trauma in aircraft craft.

• 한국시뮬레이션학회논문지
• /
• 제8권4호
• /
• pp.25-31
• /
• 1999

To analyze the impulsive response of a motorcycle helmet, a simulation is performed using the finite element method. Based upon the simulation result, an equivalent one degree of freedom vibrational system is adapted, and transient impulsive responses are analysed to investigate the influence of engineering parameters such as damping, natural frequency, and impact velocity on the impulsive response of the helmet. Maximum gravitational acceleration reduces as the damping factor value increases. When the damping factor value is around 0.6 or larger, the maximum acceleration does not change. With respect to the natural frequency and the impact velocity, it increases linearly. The relationship between head injury criterion(HIC) and maximum gravitational acceleration is also presented. The scheme of this study is expected to be utilized to economize the design process of high quality motorcycle helmets.

• 한국응급구조학회지
• /
• 제27권2호
• /
• pp.7-17
• /
• 2023

Purpose: This study aimed to identify the factors that contribute to head injuries among drivers of personal mobility devices and provide insights into safety perceptions. Methods: This retrospective study analyzed data of 221 trauma patients obtained from electronic medical records and the National Emergency Department Information System (NEDIS) over one year, from August 1, 2021, to July 31, 2022. The patients, all in their 20s and 30s, presented to a single emergency medical center following personal mobility device accidents (motorcycles, electric scooters, and bicycles). Results: Among motorcycle riders, 18.2% were not wearing helmets, while the percentage of e-scooter riders not wearing helmets was 87.5%. Wearing a helmet was associated with a 71.2% lower likelihood of head injuries (OR=0.288, CI=0.163 to 0.509, p=0.000). Of the personal mobility devices, motorcycles had a 0.431 times lower odds ratio for head injury compared to e-scooters (p=0.009), and there was no significant difference between e-scooters and bicycles (p=0.776). Conclusion: It is imperative to strengthen safety regulations by mandating helmet use for riders of personal mobility devices. A system to enhance driving enforcement for electric scooters, which are increasingly popular among young adults, should also be established.

• 대한간호학회지
• /
• 제23권4호
• /
• pp.585-601
• /
• 1993

Data on 63 patients who had had motorcycle accidents and who were admitted to four general hospitals in the Chung Chung Nam Do area from July / 1993 to August 1993 were analyzed. The tool used for this study was a structured questionnaire which consisted of ten items on self- esteem, 18 items on health locus of control and 37 items profiling health prometion lifestyle. Injury severity scores were calculated bated based on data from the patients’ medical records. The collected data were analyzed using the SPSS, yielding descriptive statistics, t-test, ANOVA, Pearson’s Product Moment Correlation. The findings of this study are as follows. 1) Of the 63 injured motorcyclists, 35(55.6%) were helmeted and 28(44.4%) were nonhelmeted, and the nonhelmeted motorcyclists were predominantly young and male. The demographic variables for the helmeted and nonhelmeted groups were heterogeneous for age and occupation. 2) The results of the comparison between the two groups showed a statistically significant difference in the injury severity score(t=-4.70, p=0.000). The helmeted group had lower scores on injury severity score (9.00±3.93) than the nonhelmeted group(14.32土5.05). More than 60% of the nonhelmeted motorcyclists had brain injuries compared to only a third of the helmeted cyclists. 3) There .was a statistically significant difference between the two groups on self esteem(t=4.5, 000). The helmeted group had a higher mean score (31.27±2.72) than the nonhelmeted group(27.46±3.80). 4) The means for Internal health locus of control (IHLC), Powerful others health locus of control (PHLC), and Chance health locus of control (CHLC) in the two groups were similar to instrument norms reported in other literature. The mean scores on the IHLC in the two groups were higher than scores on the PHLC or the CHLC. However, there was a significant difference between the mean scores for the two groups on the PHLC (t=2.85, P=0.006). 5) The mean score for the helmeted group on the health promotion lifestyle profile was higher than the mean score for the nonhelmeted group(107.30±11.10, 96.57土 15.54 respectively), and there was a significant difference between the mean scores (t=3.64, p=0.001) . The highest score for helmeted group on the health promotion lifestyle profile was in the health care domain. However, for the nonhelmeted group the highest score was in the exercise domain and the lowest score was in the health care domain. 6) With regard to the relationship between health promotion lifestyle, health locus of control and self esteem in the two groups, the correlation coefficient between health promotion lifestyle and internal health locus of control for the helmeted group was 50(p〈0.01). For the nonhelmeted group, there was no correlation between health promotion lifestyle and internal health locus of control. However, there were significant correlation between health pro-motion lifestyle and external locus of control(r=0. 46, p〈0.01), and self esteem(r=0.495, p〈0.01). 7) Among the demographic variables, age and education had an impact on individual’s self-esteem The modifying factors of age made a contribution to explaining health - promoting lifestyle. In the present study, more than 40% rf the motorcyclists were riding without a helmet. The incidence of brain injury for patients riding without a helmet was nearly twice as high in the nonhelmeted rider as compared to the helmeted rider. The nonhelmeted motorcyclists in this study had lower self-esteem, obtained a higher score on the IHLC, and were not strongly engaged in performing health promotion activities as compared to the helmeted riders. However, some of the nonhelmeted riders who had a strong belief in PHLC were positively associated with engaging in health promotion activities. Based on the results obtained from this study, strategies to promote helmet usage for motorcyclists have to be developed.